Door latch



June 1, 1954 W. Af @ILL l 2,680,036I

- At'iorney June l', 1954 w. A. GILL 2,680,036

` DooR LATCH Filed March 1, 195o 3 Sheets-Sheet 2 Patented June 1, Y1954 UNITED STATES PATENT OFFICE Claims priority, application Great Britain March 1, 1949 3 Claims. (Cl. 292-170) This invention relates to latches, more particularly for doors and the like, and has for its principal object the provision of a novel and improved form of door latch which offers advantages over those latches which are known and used at the present time.

Amore specic object of the invention is the provision of a door latch having a spring-urged locking bolt and catch means for positively retaining the bolt in its locking position until the said catch means are released by the operation of a handle or key.

A further object of the inventionis the provision of such a latch having a release member which is automatically operated as the door nears its closed position to release the catch and thus allow the door to close without it being necessary to operate the handle.

'Yet another object of the invention is the pro- Vision of a novel and improved means for operating a door latch, which means are particularly well adapted to be operated by pushing or pulling a handle towards or away from the face of the door.

Yet another object of the invention is the provision of such a latch operating mechanism which comprises an operating rod which is slidably mounted for movement transverse to the plane of the door and which is formed with a cam face or faces which engage an actuating member by the movement of which the latch may be released.

Further objects of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings.

In the drawings:

Figure l is a side view, taken partly in section, showing one form of door latch constructed in accordance with the invention, one side plate of the latch casing being removed to show the internal parts;

Figure 2 is a front view of the latch shown in Figure 1;

Figure 3 is a section taken on the line III- IIT of Figure l;

Figure 4 is a section taken on the line IV--IV of Figure 1;

Figure 5 is a section taken on the line V-V of Figure l, showingr the latch fitted to a door;

Figure 6 is an end View of one of the handles shown in Figure 5 for operating the latch;

Figures 7 and 'la show, in face and edge views, respectively the side cover plate which has been removed from the latch shown in Figure 1;

Figure 8 is a detail View showing part of the latch;

Figures 9 and 9a show in front and end views respectively a striking plate which is intended to be used in conjunction with the latch of Figures l to 8;

Figure 10 is a side view, partly broken away and in section, showing a modied iorm of latch according to the invention;

Figure 11 is a section taken on the line .XI-XI of Figure 10;

Figure l2 is a section taken on the line XII-XII of Figure l0;

Figure 13 is a section taken on the line XIII-XIII of Figure 10, showing the latch tted in a door and provided with an operating handle;

Figure le is a detail perspective View showing a part of the latch of Figures 10 to 13.

Referring rst to Figures l to 9a, the latch comprises a casing I, which consists of top, bottom and back walls, 2, 3 and i respectively, and of two side plates 5 and The plate 6 has been removed from the latch shown in Figure l but is shown separately in Figure '7. This side plate is adapted to be secured to the body of the casing by means of screws passed through holes I in the side plate and screwed into tapped holes 8 formedin the casing. The side plate 5 may be secured to the body of the casing in a similar manner to the plate or it may be welded or otherwise permanently secured to the top, bottom and back walls 2, 3 and 4.

The casing I is mounted on the back of a face plate 9, which plate is intended to be sunk in the edge of the door in the usual manner and to be secured in position by means of screws passed through holes I0 formed in the face plate.

The face plate 9 is formed with suitable holes to allow the projection of the ends of two bolts I2 and I3, which bolts are slidably mounted within the casing I. The upper of these bolts I2, which is slidably mounted between the top wall 2 of the casing and a guide I4 ntted in the latter, acts as the main locking bolt. It is urged to its locking position by means of a. compression spring I5 which is fitted in a bore formed in the bolt and which bears against the back li of the casing.

The lower bolt I3 is the release bolt. It is mounted between the guide It and a further guide IB and is urged outwardly by means ci a spring l1 tted in a bore in the bolt and bearing against a block i8. This block I8 is fitted in the casing and is secured to the back wall d by means of a screw I9.

The projecting end of the bolt I2 is provided with a roller 2l which is tted in a recess formed in the end of the bolt and which is rotatably mounted on a stud or pin 22. Similarly the bolt I3 is provided with a roller 23 which is mounted onastud24.

The locking bolts I2 is normally retained in its locking position by means of a handle-controlled catch or member 35 the upper end of which operates in a recess 3l formed in one side of the bolt I2. This catch 3Q passes slidably through cut-outs formed in the guides ld and I6 and is provided at its lower end with a horizontal platform or laterally extending part 32. A spring 33 urges the catch 30 upwardly into the position in which its front upper corner 34 engages the step 35 of the bolt I2.

The catch 3G is provided at its upper end with an extended tooth 3l which is formed on its underside with a cam face 38. When the catch 30 is drawn down, this cam face 38 engages a stud 35! which is provided on the bolt This engagement takes place at the time when the corner 34 of the catch 3@ clears the bolt I2 so that continued downward movement of the catch has the effect Aof retracting the bolt.

A cam lever @l is pivoted at 4I to a lug projecting from the back of the face plate 9. The end of this lever or part et rests on the platform 32, while its upper portion is formed with a cam face t2 which is adapted to be engaged by the inner end of the release bolt I3.

Referring now to Figures 9 and 9a, this shows the striking plate which is used in conjunction with the latch of Figure l. This striking plate 50 which is intended to be attached to the door frame by means of screws (not shown) passed through screw holes I formed in the plate, is formed with a central opening 52. It will be noted that the upper portion 53 of this opening, which is intended to receive the locking bolt I2, is narrower than the lower portion 54 which is intended to receive the release bolt I3, while the plate is provided with side lips or extensions 55 which are adapted to be engaged by the release bolt i3 before the locking bolt strikes the edges 5B of the striking plate.

It will thus be seen that as the door closes, the release bolt I3, striking the lip 55, will be operated to disengage the catch 30 from the bolt I2 before this latter bolt strikes the edge 56 of the striking plate. Thus the bolt I2 can move inwardly to permit the door to close. Should the swelling of the door or other causes result in the locking bolt not retracting easily when it engages the striking plate, the movement of the cam tooth 3l' will, of itself, result in the continued movement of the release bolt I3 retracting the locking bolt I2.

A stud 58, the purpose of which will be explained, is provided on the bolt i3 engaging in a slot 5S formed in the underside of the bolt I2. The slot 59 is made of such a length as to ensure that the catch 38 is disengaged from the end of the bolt I2 before the stud 58 engages and operates the latter. The two bolts thus have a lost-motion connection.

Owing to the provision of the rollers 2l and 23 on the ends of the bolts I2 and I3 an opening pressure applied to the door would be sufficient to force in the bolts but for the catch 3B which locks the bolt I2. It will be appreciated that the widened portions 54 of the opening in the striking plate 50 ensure that when the door is closed the release bolt I3 cannot be forced in to release the catch 3G by engagement with the striking plate. In order to vopen the door, therefore, it is necessary to operate a handle provided for the purpose.

CII

Such a handle is shown at 6I in Figures 5 and 6 while a second similar handle 52 is provided on the opposite side of the door, it being understood that the latch described is intended for use on a double-acting or swing door.

The handle 6I is pivoted at its lower end to a link 53 which in turn is pivoted at 54 to a bracket 65 mounted on the face of the door. Alternatively, the handle 5I could be pivoted directly to the bracket 55 providing that a small working clearance is allowed at the joint to permit the angular movement of the handle.

At its upper end the handle 6I is pivoted at S5 to a boss El which is screwed on to the end of an actuating rod 68 which passes through the door and through the latch casing mounted therein. The other end of this rod 58 is also screwed for attachment to the boss G9 (corresponding to the boss 5l) to which the handle 52 is connected at it-s upper end. Flanged sleeves or guards 'l5 and II which are attached to the door surround the ends of the rod GS and the necks of the bosses 61 and 59.

Where the actuating rod t8 passes through the latch casing it is provided with an enlarged part 'i3 of square external section. This part I3 of the rod 58 is formed with a generally arcuate cam recess i4 in which an actuating ball or element 1'5 engages, this ball operating in a vertical bore formed in the block I6.

Compression springs I5 and l'I surround the ends of the actuating rod 68 between the body of the latch casing and the bosses iI and 69 of the handles 5I and 52. These springs serve to centre the actuating rod 68 and to return it to the position shown after it has been displaced in either direction by a push or a pull applied to one of the handles 6i and 52.

The ball 'I5 rests on the head Bil of a hollow stud 8l the stem of which is fitted loosely in a hole formed in the platform 32. A compression spring B2 forces the stud 8l upwardly and keeps the ball in engagement with the actuating rod 58.

It will be clear that when either of the handles 5I and 62 is operated either inwardly or outwardly the eiect will be to force the ball 75 and with it the catch 33 downwardly, thus disengaging the latter from the locking bolt I2. Mere pressure on the door should then be sufficient to force the bolt I2 (and also the bolt I3) inwardly, thus allowing the door to open, but should it fail to do so owing, for example, to the swelling of the door, the engagement of the cani tooth 3l with the stud 39 will ensure the retraction of the bolt I2, which, by engaging the stud 55, will retract the bolt I3.

Owing to the movement permitted between the stud BI and the platform 32 the former will maintain the ball 'I5 in engagement with the rod `68 when the platform '32 is depressed by the bolt i3 and lever flil during the closing of the door.

It would be possible for the lower ends kof the springs 33 and 82 to rest on the bottom 3 of the casing, but in the vconstruction shown .the lock is provided with an additional key-operated catch SIl and the lower ends of these springs are arranged to press on a platform or projection SI provided on this catch in order to control the latter.

The catch extends up within .the casing beside the catch .30 .and its upper end is adapted to engage the step or shoulder 35 ofthe bolt I2 in a similar manner to the catch 30.

The catch 90 is operated by means of a tongue 92 which engages a cam face 93 formed on the underside of a projecting arm portion 94 of the catch. When the tongue 92 is in the position shown in Figure 1 the catch 190 is in its lower position so that its upper end is clear of the bolt |2. When, however, the tongue 92 is turned in a clockwise direction (Figure 1) towards the end 95 of the cam surface 93 the catch 90 is raised and locks the bolt.

The tongue 92 may be operated by any suitable key, or other member iitted in a slot 96 cut in the cylinder 91 carrying the tongue 92 and it may be controlled by any suitable lever, cylinder or other lock mechanism. This mechanism may be provided as an integral part of the latch or the slot 96 may be designed to receive the voperating rod of a separate lock, for example one of the cylinder type, mounted in or on the door.

Figures to 14 show a modified form or latch which is of a simplied and cheaper construction. This latch comprises a casing |0| which is mounted on the back of a face plate |02. It may be cast integrally with the latter, if desired.

The casing |0| is formed with two parallel bores |03 and |04, of circular cross-section, Within which are slidably mounted two bolts |05 and |06 respectively. The ends of these bolts carry rollers |01 and |08 respectively and project through suitable apertures formed in the face plate |02.

The upper bolt |05, which is the locking bolt, is urged to its locking position by means of a spring |09 which is tted in a bore ||0 formed in the bolt and which reacts against the base of the bore |03.

Similarly the bolt |06, which is the release bolt, is urged outwardly by means of a spring which is fitted in a bore ||2 formed in the bolt. The rear end of the spring abuts against a catch ||3 (see also Figure 14) which is slidably mounted in suitable recesses formed in the casing |0|.

The upper end of the catch ||3 is adapted to engage the rear end of the locking bolt |05, while at its lower end the catch ||3 is provided with a cross piece or part ||4, the upper surface of which is of rounded or cam shape and engages the rear end of the bolt |06. The vertical portion or stem of the catch |I3 passes through a slot ||5 formed in the rear part of the bolt |06, the length of this slot being sufficient to allow the bolt |06 to be fully retracted. It will be seen that as the release bolt |06 is pressed inwardly its cam-shaped inner end engages the cam surface of the cross piece or element ||4 and thus vforces the catch ||3 down to release the locking bolt |05.

rlhe movement of the bolts |05 and |00 is limited by a Din |6 which is fitted in a transverse bore formed in the casing |0| and which engages in slots ||1 and ||8 formed in the under and upper sides, respectively, of the bolts |05 and |06.

The catch I3 is normally held in its upper position by means of a pair of small springs ||9 which are fitted beneath the cross-piece |4.

As in the case of the latch described with reference to Figures 1 to 8 the latch of Figures 10 to 14 is double-acting and is intended to be mounted on a swing door provided with a handle on each side. Figure 13 shows the latch fitted to a door, one only of the handles being shown at |20.

This handle is pivoted at its lower end (not shown) to the door in a similar manner to the handle 6| of Figure 5. At its upper end the handle |20 is pivoted at |2| to a boss |22 which is screwed on the end of an actuating rod |23 which passes through the door and through the latch casing. The boss |22 is slidable in a socket |24 mounted on the face of the door and is urged outwardly by means of a spring |25 which is fitted in the socket and extends into an annular recess |26 formed in the boss |22.

There is Van exactly similar handle assembly (including a spring corresponding to the spring |25) on the other side of the door attached to the other end of the rod, |23, and the two springs tend to return the rod in its central position.

Where the rod |23 extends through the latch casing it passes through a cam sleeve |30 which is slidably mounted in a transverse bore formed in the casing |0|. Two spacing sleeves v|32 are fitted on the rod |23, clamped between the bosses |22 and the cam sleeve |30. Consequently, longitudinal movements of the rod |23 are transmitted to the cam sleeve |30.

On its underside the cam sleeve |30 is formed with a cam recess |33 of approximately arcuate form. An actuating ball |34, which is fitted in va vertical bore |35 formed in the casing, en-

gages in the cam recess |33.

The ball |34 is urged upwardly by means of a sleeve |36 which is acted on by a spring |31. The lower end of this spring is supported on a bottom plate |38 which is attached to the bottom of the casing |0|, while its upper end bears against a tapered pin |39 which passes transversely through the sleeve |36. An end of this pin |39 engages in a cut-out |40 in the catch I3 so that the downward movement of the sleeve |36 depresses the catch ||3 and disengages the latter from the locking bolt |05.

The latch of Figures 1|) to 14 is intended to be used with a striking plate similar to that shown in Figure 9 and the operation of the latch will be clear from the foregoing description.

When the door is closed the locking bolt |05 is held in its locking position by the catch ||3. To open the door pressure in either direction is applied to one of the handles |20. The resulting movement of the actuating rod |23 and cam sleeve |30 depresses the ball |34 and thus the sleeve |36 and catch ||3. This frees the locking bolt |05 and allows the door to open when pressure is applied to it.

The operation of the release bolt |06 allows of the door being closed without touching the handles, since when the bolt |06 engages the striking plate it depresses the catch ||3 and thus frees the locking bolt |05.

Both of the latches which have been described are double-acting and are suitable for use on doors of the swing type which open in either direction. The latches could, however, easily bc adapted for doors opening in one direction only. In such cases a suitable stop might be provided to limit the movement of the actuating rod from its central position to one direction only.

If desired the actuating balls 15 and |34 could be replaced by rollers, while other modifications could also be made in the latch without departing from the invention.

In the preceding description the handles 6| and |20 have been assumed to be mounted vertically but they could clearly be mounted horizontally on the door or in any other desired position. They could, for example, take the form of long horizontal bars such as are provided on the doors of theatres, cinemas and other places of public entertainment, to ensure that in the event of a panic the doors will be opened by the pressure of the crowd.

I claim:

1. In combination, a latch to be secured to a door adjacent a striker plate to be secured to a door jamb, the latch including a casing, a locking bolt and arelease bolt, said bolts being spaced apart in said casing and being in line With separate portions of said plate, yielding means to move each bolt in a direction to project one end thereof from the casing into a position to engage said separate portions of the striker plate when the door is closed, said ends being formed with surfaces facing in both directions for movement of the door, a catch movable into engagement with the locking bolt for the retaining of the latter in its projected position, a handle, means connecting the handle with the catch to release the catch from the locking bolt to permit inward retraction of the locking bolt by pressure exerted on the locking bolt by the striker plate as the door is opened, the release bolt being mounted to be movable independently of the locking bolt and also retractable by inward pressure exerted thereon by the striker plate as the door is closed, and the catch having a part in a position to be actuated upon inward movement of the release bolt without movement of the handle to withdraw the catch and allow retraction of the locking bolt by inward pressure exerted thereon.

by the striker plate upon further closing movement of the door.

2. In combination, a latch to be secured to a door adjacent a striker plate to be secured to a door jamb, the latch including a casing, a lockin;r bolt and a release bolt, said bolts being spaced apart in said casing and being in line with separate portions of said plate, yielding means to move each bolt in a direction to project one end thereof from the casing into a position to engage said separate portions of the striker plate when the door is closed, said ends being formed with surfaces facing in both directions for movement of the door, a catch movable into engagement with the locking bolt for the retaining of the latter in its projected position, a handle, means connecting the handle vwith the catch to release the catch from the locking bolt to permit inward retraction of the locking bolt by pressure exerted on the locking bolt by the striker plate as the door is opened, the release bolt being mounted to be movable independently of the locking bolt and also retractable by inward pressure exerted thereon by the striker plate as the door is closed, and the catch having a part in a position to be actuated upon inward movement of the release bolt without movement of the handle to withdraw the catch and allow retraction of the locking bolt by inward pressure exerted thereon by the striker plate upon further closing movement of the door, the means connecting the handle and the catch comprising a longitudinal movable bar extending transversely of the casing and having a cam portion and an element between the bar and the catch to be actuated by said cam portion.

3. In combination, a, latch to be secured to a door adjacent a striker plate to be secured to a door jamb, the latch including a casing, a locking bolt and a release bolt, said bolts being spaced apart one above the other in said casing and being in line with separate portions of said plate, yielding means to move each bolt in a direction to project one end thereof from the casing into a position to engage said separate portions of the striker plate when the door is closed, said ends being formed with surfaces facing in both directions for movement of the door, a catch mounted to be movable transversely of said bolts, a spring in the casing engaging the cat-ch to move the catch, into engagement with the locking bolt for the retaining of the latter in its projected position, a handle, means connecting the handle with the catch to release the catch from the locking bolt to permit inward retraction of the locking bolt by pressure exerted on the locking bolt by the striker plate as the door is opened, the release bolt being mounted to be movable independently of the locking bolt and also being retractable by inward pressure exerted thereon by the striker plate as the door is closed, the catch having a laterally extending part in a position to be actuated upon longitudinal movement of the release bolt without movement of the handle to render the catch temporarily inoperative and allow retraction of the locking bolt by inward pressure exerted thereon by the striker plate upon closing movement of the door.

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